Simulation of particle size distribution and source term for uranium aerosols based on zinc generated under fire conditions

Min Zhu,Biao Li,Yanjun Wang,Hanyuan Mao,Zhaoyi Tan,Ming Guo,Fei Wu,Liang Du

doi:10.1063/5.0075705

Abstract

Fire is a typical scenario for nuclear accidents, in which uranium-containing materials will release uranium aerosols. Limited by many aspects, uranium aerosols cannot be used directly to carry out nuclear emergency training and equipment development research under real conditions. Therefore, it is necessary to filter and evaluate available surrogate materials through experiments. In this paper, metallic zinc is used to study the source term and particle size distribution of zinc aerosols under fire conditions, and the feasibility of zinc as a surrogate material for uranium aerosol research is evaluated based on the data of uranium aerosols in the literature. The experimental results show that the mass median aerodynamic diameter obtained by fitting with lognormal distribution is between 0.36 and 0.59 µm. The cumulative mass fraction distribution data are consistent with those given in the literature, indicating that the zinc aerosols generated under fire have a nice simulation effect on uranium aerosols in terms of particle size distribution. As for air release fraction (ARF) and respirable fraction (RF), the experiment of zinc aerosols is greater than that of uranium aerosols, which means the simulation in ARF and RF is not so good.

Highlights

While the widespread application of nuclear technology brings progress to society, it creates a series of nuclear safety risks (Antill and Peakall, 1959; Megaw et al, 1961)
Studies on the hazard of uranium aerosols have shown that aerosol particles with an aerodynamic equivalent diameter (AED) smaller than 10 μm can enter the human body through the respiratory tract and deposit in different parts according to the particle size
The potential reason is that the transmission pipeline of the sampling system in this experiment is too long, and during the transportation process, the large particles may deposit on the inner walls of the pipeline because of greater inertia, resulting in larger respirable fraction (RF)

Summary

Introduction

While the widespread application of nuclear technology brings progress to society, it creates a series of nuclear safety risks (Antill and Peakall, 1959; Megaw et al, 1961). Studies on the hazard of uranium aerosols have shown that aerosol particles with an aerodynamic equivalent diameter (AED) smaller than 10 μm can enter the human body through the respiratory tract and deposit in different parts according to the particle size. Afterward, they can cause harm to the human body through chemical toxicity and internal radiation (Petrina, 2008; Roszell et al, 2009; and Zhou, 1996). Studying the generation characteristics of aerosols in the uranium-containing system under fire conditions, especially its source term and particle size distribution, is an important part of nuclear safety analysis and evaluation (Di Lemma et al, 2014; Surya Narayana et al, 1994)

Methods

Results

Conclusion